The manufacturer of GRIPPER tires modeled its return to sales from television advertising expenditures in two regions, as follows: Region 1: S_1 = 50 + 28x_1 - 0.4x_1^2 Region 2: S_2 = 30 + 26x_2 - 1.1x_2^2 where S_1 and S_2 are the sales revenue in millions of dollars and x_1 and x_2 are millions of dollars of expenditures for television advertising. (Round your answers to three decimal places.) What advertising expenditures would maximize sales revenue in each district? Region 1 $ million Region 2 $ million How much money will be needed to maximize sales revenue in both districts? $ million